Weaving of ribbons

ABSTRACT

Ribbons are woven and then withdrawn tautly in a specific path. When, in response to the occurrence of a weaving fault, the ribbons undergo displacement in the general plane temporarily so that slack will temporarily occur in the respective ribbon permitting the latter to return or be returned to its original position in the path.

O United States Patent 1 1 1 1 ,6

Essig 5] Apr. 17, 1973 [541 WEAVING OF kIBBONS 2,515,897 7/1950 Angus etal ..139/115 [75] Inventor: Erich Essig, Frick, Switzerland FOREIGN PATENTS OR APPLICATIONS Assigneel Jakob Muller, Frick, Switzerland 682,481 2 1930 France ..139/291 R Filed: J y 1971 338,356 6/l92l Germany 139/313 [21] Appl. No.: 162,118 Primary Examiner-Henry S. Jaudon Attorney-Michael S. Striker [30] Foreign Application Priority Data 57] ABSTRACT Aug. 4, 1970 Germany ..P 20 38 601.1 Ribbons are woven and then withdrawn tauuy in a specific path. When, in response to the occurrence of [52] CLW I 139/313 a weaving fault, the ribbons undergo displacement in [51] Int. Cl. ..D03d 49/22 h general m temporarily so that Slack will Field of Search 35, 114, 115, porarily occur in the respective ribbon permitting the 1 316 latter to return or be returned to its original position in the path. [56] References Cited 9 Claims, 7 Drawing Figures UNITED STATES PATENTS 799,804 9/1905 Schaurn ..l39/3l6 WEAVING or RIBBONS BACKGROUND OF THE INVENTION The invention relates generally to the weaving of ribbons, and more particularly to an improved apparatus and method attendant to the weaving of ribbons.

Ribbon looms are usually of the type on which a plurality of ribbons are being woven simultaneously, rather than weaving a single ribbon at a time. These ribbons are all withdrawn simultaneously in taut condition. Depending upon the quality of the weft threads used in weaving, such looms have a more or less frequent problem with breakage of weft threads in which case the ribbon where such breakage occurs will have a fault where a plurality of weft threads-usually between four and eightare missing, so that a fault or gap exists in which only warp threads are present. Even rapidly operating thread breakage detectors cannot avoid the occurrence of such faults once the weft threads break.

On the other hand, such faults must of course be repaired unless one is prepared to discard a large portion of the ribbon with the fault, because obviously the ribbon cannot be sold with the fault which is highly visible. To effect such repair the ribbon is retarded by an amount which corresponds to the quantity of missing weft threads, that is the space taken up by the missing number of weft threads. According to the prior art this is accomplished in that the ribbon having the fault is either released from the associated withdrawing device or it is loosened by removing the pressure rollers which press it against the transporting rollers of the withdrawing device. In either case it can be withdrawn oppositely its normal direction of advancement and the missing weft threads can then be inserted. The delaying operations which are necessary in the prior-art constructions are, however, time-consuming, especially if the withdrawing device for the ribbons is of the type utilizing spring-biased rollers. It need hardly be pointed out that the longer the time is which is required for retarding a ribbon after a weft thread breakage has occurred, the less economical will be the operation of the loom because of the necessary work stoppage.

These problems are all aggravated by the fact that in order to properly repair a fault resulting from the breakage of weft threads, it is essential that the faulty ribbon be retarded by an exactly right amount. If it is retarded to an insufficient extent, then a thin spot will result at the fault, that is the fault will be inadequately repaired and such spots are sometimes known as note paper. If, on the other hand, the ribbon is retarded too much, then the weft threads will dam and will make a thick fault. The regulation of the accuracy of retardation is made especially difficult if it is possible to retard the ribbon only by disengaging at the withdrawing device, as was heretofore universally the case, because the operator cannot properly observe the entire elongation of the ribbon and the location of the fault, so that high skill and great experience are necessary in order to retard the ribbon by at least approximately the correct amount.

SUMMARY OF THE INVENTION It is of course obvious that under the existing circumstances improvements are highly desirable, and consequently it is a general object of the present invention to provide such improvements.

More particularly it is an object of the invention to provide an improved apparatus which will overcome the disadvantages of the prior art.

A concomitant object is to provide a method of carrying out the aforementioned operations without incurring the disadvantages of the prior art.

In pursuance of the above objects and of others 1 which will become apparent hereafter, one feature 'of the invention resides in a ribbon loom which, briefly stated, comprises ribbon weaving means and ribbon withdrawing means for withdrawing woven ribbon in taut condition from the weaving means in a withdrawal path. According to the invention there is further provided ribbon deflecting means comprising at least one shaft extending transversely of the path and at least one roller having a peripheral face one portion of which is smooth and another portion of which is rough, and being eccentrically mounted on the shaft for movement between two end positions in one of which the ribbon slides over the one portion during its movement in the path and another position in which the ribbon slides over the other portion and the latter is offset to one side of the general plane of the path.

With this construction it is possible to very rapidly provide for the retardation or slackening of a faulty ribbon, and at the same time it makes it possible to readily and accurately supervise the extent of retardation or slackening.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic side view illustrating those components of an embodiment of the invention which are necessary for an understanding, during the weaving operation;

FIG. 2 is a view similar to FIG. I but illustrating the embodiment after retardation;

FIG. 3 is an intermediate position of the embodiment in FIGS. 1 and 2, that is showing the embodiment before it returns from the position of FIG. 1 to that of FIG. 2;

FIG. 4 is a view similar to FIG. 1, illustrating a further embodiment of the invention;

FIG. 5 is a view similar to FIG. 4 illustrating another embodiment of the invention;

FIG. 6 is a diagrammatic illustration of portions of a weaving loom provided with the novel device and FIG. 7 is a somewhat diagrammatic front view showing two of the rollers extending across the loom of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing the drawing now in detail, and firstly the embodiment illustrated in FIGS. 1-3, it will be seen that reference numeral 1 identifies a shaft on which a deflecting roller is mounted eccentrically. The portion 3 of the circumferential or peripheral face of the roller 2 is smooth whereas the portion 4 is rough, either being generally roughened, provided with knurling, grooves or the like. The woven ribbon is woven by the weaving loom at the right-hand side of the roller 2 and is withdrawn by the withdrawing device towards the lefthand side of the roller 2 in the direction of the associated arrow, neither the loom nor the withdrawing device being illustrated for the sake of clarity. The ribbon 5 is normally maintained taut and withdrawn in a predetermined path.

In the position which the roller assumes in FIG. 1 and which is the normal position in which the roller is located when no fault is present in the ribbon 5, it will be seen that the roller 2 is located in its highest eccentric position abutting against an abutment 6which is preferably adjustablewith its region 3 facing upwardly. The ribbon 5 contacts the region 3 and slides without hindrance over this region on its path to the withdrawing device.

If, now, one or more weft threads break at the righthand location, that is to the right of the roller 2 where the weaving takes place, that makes it necessary to temporarily reverse the movement of the ribbon 5, that is to slacken it in the direction opposite to its direction of movement which is indicated by the arrows. To achieve this the roller 2 is turned in direction of the arrow X, so that it moves to its lowest position which is illustrated in FIG. 2 and in which the smooth region 3 faces downwardly whereas the rough region 4 now faces upwardly and contacts the ribbon 5. As the roller 2 moves to the position of FIG. 2, the ribbon is slackened and can now be drawn backwardly towards the right in FIG. 2. When subsequently the weaving apparatuswhich has been shut down for this repair or adjustmentis started up again, the roughness of the region 4 in contact with the ribbon 5 causes the latter to take along the roller 2 upwardly in the direction of the arrow X, meaning that the roller 2 moves back and passes the intermediate position illustrated in'FIG. 3 until it reaches the position illustrated in FIG. 1 and is prevented from further movement by contacting the abutment 6. During this movement, the roller 2 again presents its surface region 3 to the ribbon, so that the latter can now again slide freely over this region 3 and move in its predetermined withdrawing path. If a subsequent weft thread breakage occurs, the preceding operation is again carried out. It will be evident that the roller 2 may be moved to the FIG. 2 position by hand, if desired with the aid ofa suitable handle or the like.

Some ribbons are woven with low tension and/or have a very smooth or slippery surface. To avoid that under such circumstances the ribbon cannot slide over the rough region 4 of the roller 2 without taking the roller along from the position of FIG. 2 back to the position of FIG. 1, the embodiment of FIG. 4 provides a counter-roller 7 which is advantageously spring-biased by a spring 8 which may abut against a bracket 9, so that the roller 7 presses the ribbon against the circumference ofthe roller 2. This assures a better contact of the ribbon 5 with the region 4 of the roller 2 and guarantees that the ribbon, if it is woven under low tension and/or is slippery, will nevertheless take the roller along from the position of FIG. 2 back to the position of FIG. I after a fault has been repaired.

The embodiment of FIG. 5 has the same purpose as the embodiment of FIG. 4, meaning that it is intended to ensure better contact of the ribbon with the roller. Here, the roller 2 is not mounted directly on the shaft 1 which normally is directly mounted in non-illustrated bearings. Instead, the roller 10 (or the shaft with respect to the bearings of the latter) will be mounted with the interposition of an advantageously adjustable tension spring 10 which is tensioned when roller 2 is turned from the FIG. 1 position to the FIG. 2 position in the direction of the arrow X. Tension spring 10 can of course be replaced by a torsion spring. When the loom is restarted after a fault is repaired, the tensioned spring 10 -in its tendency to relax-aids the stepwise return of the roller 2 counter to the direction of the arrow X to the normal position as shown in FIG. 1. This makes it possible for the ribbon to return the roller 2 back to its normal position even if the weaving tension is low or if the ribbon has a very smooth, slippery surface.

It will be appreciated how the novel device according to the present invention is associated with the other components of a ribbon-weaving loom. For information I have, however, illustrated this diagrammatically in FIG. 6 and 7 where reference numeral 11 identifies the frame and 12 the swingably mounted beam whose supports 13 (only one shown while the other is located spaced from it in a plane normal to that of the drawing) swing about the axis 14. The element 12 is driven by the crank drive 15 which turns about the main shaft 16 and is connected with the element 12 by the linkages 17. The shed formation of the warp 18 takes place via two members 19 (one shown) which are operated by any well known actuating device and move in the direction of the double-headed arrow y. The weft threads are inserted in this embodiment by means of shuttles 20, but could also be carried out by other means such as needles.

In the embodiment here shown, the finished woven ribbon 5 is not passed to the withdrawing device 21 via a stationary breast beam, as is customary in the prior art. Instead, it is passed over the roller 2 of which one is provided for each ribbon woven on the loom. In FIG. 7 the rollers 2 are shown in different positions for purposes of explanation. The withdrawing device 21 has two driven rollers 22 and 23 and a pressure roller 24 which presses the ribbon 5 against the driven rollers; it will be noticed that the ribbon 5 is placed about the roller 22, whereupon about the roller 24 and then passes between this and the roller 23 out of the device 21 to move downwardly into a non-illustrated container. It is this convolution of the ribbonabout the withdrawing rollers which makes it difficult in the prior art to loosen it for obtaining the necessary slack. When in one of the many ribbons which are woven simultaneously on the ribbon weaving loom, one of the described faults occurs, resulting from breakage of the weft thread, then it is very difficult to loosen the ribbon in the withdrawal device 21 and to slacken it in order to return the lateral abutment edge 25 into line with the abutment edges of the other ribbons, that is until it is returned to its original path from which it had moved .with reference to the roller 2 as a result of the breakage of the weft threads. This is accomplished in accordance with the present invention by moving the roller 2- which is normally in the position A corresponding to that shown in FIG. l-to the position B corresponding to that shown in FIG. 2. When this takes place, the ribbon 5 assumes the position 5, that is it is deflected to one side of the general plane of the withdrawal path in which it normally moves when the roller 5 is in the position A, so that it becomes slackened and the abutment edge 25 is thus able to return to its original position, that is the ribbon returns to its path.

When subsequently the loom is started up again the ribbon takes along the roller 2 stepwise, until it returns back to the position A as a result of frictional engagement with the roughened portion 4. Of course, during this return the weft density is somewhat smaller than during normal weaving because the withdrawal movement afforded the ribbon by the withdrawing device 21 has now added to it the return movement of the roller 2 to the position A, so that the ribbon temporarily moves slightly faster than normally. However, this density variation is so small that it no longer is seen as a fault.

In such instances in which the ribbons utilize a common sectional warping beam, an individual tensioning device can be provided for each ribbon in the loom intermediate the broad beam and the warp beam in order to prevent the warp threads of a retarded or a slackened ribbon from becoming slack, which would lead to another fault and possibly to breakages in the warp threads.

It will be appreciated that the method and device according to the present invention are not only simple but also highly efficient and very quick and saving in time. The time-consuming release of the pressure rollers on the withdrawing device is avoided. Furthermore, because the device according to the present invention can be located in the immediate vicinity of the ribbon abutment edge, the exact determination of the amount by which the ribbon has to be slackened or retarded, and which can be readily achieved by appropriate utilization of the eccentricity of the roller 2, can be easily supervised and obtained. This means that the down time resulting from fault correction of the type here in question is reduced to a minimum and the economics of the loom operation is significantly improved.

It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in the weaving of ribbons, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis the foregoing will so fully means; ribbon withdrawing means for withdrawin woven ribbon from said weaving means in a withdrawa path; and ribbon deflecting means, comprising at least one shaft extending transversely to said path, and at least one roller having a peripheral face one portion of which is smooth and an other portion of which is rough, and being eccentrically mounted on said, shaft for movement between two end positions in one of which the ribbon slides over said one portion during movement in said path, and an other position in which said ribbon slides over said other portion and the latter is offset to one side of the general plane of said path.

2. In a ribbon loom as defined in claim 1; further comprising abutment means for limiting the movement of said roller.

3. In a ribbon loom as defined in claim 1; further comprising displaceable abutment means for limiting the movement of said roller.

4. In a ribbon loom as defined in claim 1; and further comprising counter roller means extending in axial parallelism with said roller and operation for urging successive increments of the moving ribbon into contact with said peripheral face.

5. In a ribbon loom as defined in claim 1; and further I comprising spring-biased counter roller means extending in axial parallelism with said roller and operative for urging successive increments of the moving ribbon into contact with said peripheral face.

6. In a ribbon loom as defined in claim 1; and further comprising spring means operative for urging said roller for movement from said other to said one position.

7. In a ribbon loom as defined in claim 6, wherein said spring means comprises torsion spring means.

8. In a ribbon loom as defined in claim 6, wherein said spring means comprises tension spring means.

9. In a ribbon loom as defined in claim 1; further comprising adjustable tension spring means operative for urging said roller for movement from said other to said one position. 

1. In a ribbon loom, in combination, ribbon weaving means; ribbon withdrawing means for withdrawing woven ribbon from said weaving means in a withdrawal path; and ribbon deflecting means, comprising at least one shaft extending transversely to said path, and at least one roller having a peripheral face one portion of which is smooth and an other portion of which is rough, and being eccentrically mounted on said shaft for movement between two end positions in one of which the ribbon slides over said one portion during movement in said path, and an other position in which said ribbon slides over said other portion and the latter is offset to one side of the general plane of said path.
 2. In a ribbon loom as defined in claim 1; further comprising abutment means for limiting the movement of said roller.
 3. In a ribbon loom as defined in claim 1; further comprising displaceable abutment means for limiting the movement of said roller.
 4. In a ribbon loom as defined in claim 1; and further comprising counter roller means extending in axial parallelism with said roller and operation for urging successive increments of the moving ribbon into contact with said peripheral face.
 5. In a ribbon loom as defined in claim 1; and further comprising spring-biased counter roller means extending in axial parallelism with said roller and operative for urging successive increments of the moving ribbon into contact with said peripheral face.
 6. In a ribbon loom as defined in claim 1; and further comprising spring means operative for urging said roller for movement from said other to said one position.
 7. In a ribbon loom as defined in claim 6, wherein said spring means comprises torsion spring means.
 8. In a ribbon loom as defined in claim 6, wherein said spring means comprises tension spring means.
 9. In a ribbon loom as defined in claim 1; further comprising adjustable tension spring means operative for urging said roller for movement from said other to said one position. 